fix(docker): create custom template [EE-4114] (#7812)

* EE-4114 fix(docker): create custom template

* Update customtemplate_create.go

remove white space

api/http/handler/customtemplates/customtemplate_create.go

@@ -380,12 +380,14 @@ func (payload *customTemplateFromFileUploadPayload) Validate(r *http.Request) er
 	payload.FileContent = composeFileContent
 
 	varsString, _ := request.RetrieveMultiPartFormValue(r, "Variables", true)
+	if varsString != "" {
 		err = json.Unmarshal([]byte(varsString), &payload.Variables)
 		if err != nil {
 			return errors.New("Invalid variables. Ensure that the variables are valid JSON")
 		}
-
 		return validateVariablesDefinitions(payload.Variables)
+	}
+	return nil
 }
 
 func (handler *Handler) createCustomTemplateFromFileUpload(r *http.Request) (*portainer.CustomTemplate, error) {

app/portainer/views/custom-templates/create-custom-template-view/createCustomTemplateView.html

@@ -83,9 +83,6 @@
                 <button type="button" class="btn btn-sm btn-primary" ngf-select ng-model="$ctrl.formValues.File"> Select file </button>
                 <span class="space-left">
                   {{ $ctrl.formValues.File.name }}
-                  <span ng-if="$ctrl.formValues.File">
-                    <pr-icon icon="'x'" feather="true" mode="'danger'"></pr-icon>
-                  </span>
                 </span>
               </div>
             </div>